Trommel screen



June 21, J A TRAYLQR 2,121,371

. TROMMEL S GREEN Filed Feb. 26, 1936 2 SheetS -Sheet 1 NVENTOR B47102 ATTORNEYE;

June 21, 1938. J. A. TRA'YLOR TROMMEL SCREEN Filed Feb. 26, 1956 2 Sheets-Sheet 2 Fla. 4.

V I lNVENfOR.

e/fl/V/V 4. 794/108:

Y I Z44; pi ATTORNEY Patented June 21, 1938 UNITED STATES PATENT OFFICE TROMMEL SCREEN John A. Traylor, Tiger, 0010. Application February 26, 1936, Serial No. 65,933

12 Claims.

the screen plates employed is such as to cause them to rapidly wear out, requiring frequent replacement of the screen plates. Heretofore it has been the common practice to secure these plates to the spanners or skeleton structure of the trommel screen by rivets or bolts, often of special design and construction, and after a rel atively short operation of the trommel screen these rivets and bolts have become so worn and loosened that they must be replaced or re-riveted. Thus the maintenance of a trommel screen requires the frequent replacement of the worn or loosened rivets or bolts and the frequent replacement of the screen plates, either of which operations requires the removal of the rivets or special bolts and their replacement, work which requires a great expenditure of time and labor.

It is an object of my invention to provide a trommel screen in which the plates may be readily placed upon and secured to the skeleton structure and may be readily removed therefrom without the necessity of riveting or bolting the plates in place and cutting the rivets and bolts free when the plates are to be removed.

Another object of my invention is to provide a trommel screen of the character set forth wherein the plates are held in place by clamping the edges of the plates to the skeleton structure.

Another object of my invention is to provide a trommel screen wherein the screen is constructed of a skeleton frame or drum including a plurality of longitudinally extending spanners, upon the outer surfaces of which the screen plates may rest and to which outer surfaces the plates are clamped.

Another object of my invention is to provide a screen of the character set forth in the preceding paragraph wherein tie rods may be employed extending between adjacent spanners to clamp the plates to the spanners so that a single tie rod acts to clamp opposed edges of a plate to the spanners.

Another object of my invention is to provide a screen of the character set forth wherein the spanners are provided with foot portions upon the outer surface of which the edges of the plates may rest and with projecting portions extending radially between the edges of adjacent plates whereby clamping blocks may be disposed through theprojecting portions of the spanners V and will act to clamp the edges of both adjacent plates to the spanners.

Another object of my invention is to provide a trommel screen of the character described wherein the tie rod extending between adjacent spanners may be employed to reinforce or brace the plates intermediate the spanners.

Other objects as well as the nature, characteristic features and scope of the invention will be more readily apparent from the following description taken in connection with the accompanying drawings and pointed out in the claims forming a part of this application.

The invention is clearly illustrated in the accompanying drawings, in which:-

Fig. 1 is a side elevational view of a trommel screen showing improved means for fastening the cover plate sections to the screen.

Fig. 2 is an enlarged fragmentary transverse sectional view between adjacent spanners showing one embodiment of the improved means for clamping the plates in position upon the screen.

Fig. 3 is an enlarged cross-sectional view taken on line III-III of Fig. 2.

Fig. 4 is an enlarged transverse sectional detailed view of a modified form of spanner with a modified sectional block applied thereover and shown in elevation.

Fig. 5 is a cross-sectional view taken along line VV of Fig. 4, and t Fig. 6 is a cross-sectional view through a screen with spannersand blocks of the type in Figs. 4 and 5.

Similar characters of reference are employed in all of the above described views to indicate corresponding parts.

Referring to the drawings, I have illustrated in Fig. 1 a trommel screen or revolving screen comprising a skeleton frame or drum which may in this event the skeleton drum may be provided with one or more rings or bands 5 upon which the adjacent ends of the plates 4 may rest and to which they may be secured as by means of a clamping strip 6 and bolts 1.

The spanners illustrated in Figs. 1 and 2 are shown as having a substantially T-shaped cross section, the cross bar 8 of the T being disposed inwardly of the skeleton drum to constitute a foot portion or shelf, upon the outer surface of which the edge of the screen plates 4 may rest while the leg 9 of the T extends radially out- Wardly of the drum between the adjacent plates 4 resting upon the foot portions of the spanners.

A plurality of openings ii) are provided through the projecting portions or legs of the T structure of the spanner, these openings being distributed along the length of each of the spanners; through each of which .openings a wedge block I I may. be inserted. The wedge blocks H are preferably provided upon one of their sides withflattened or projecting portions .12 and I3 adapted to engage and rest upon the'outersurfaces of the edges of the plates 4 resting upon'the foot pertions 8 of the spanners, while the outer or opposite side of the wedge blocks ll maybe tapered toward the projections l2 and IS in such manner that when the wedge blocks 9 are drawn inwardly of the openings ID the flattened surfaces l2 and i3 will engage the outer surface of the two adjacent plates 4 resting upon the foot'portion and will securely clamp these plates between the wedge blocks l l and the foot portions 8 of the spanners. I prefer that this wedging action shall constitute the sole means for securing the plates to the skeleton frame so that by removing the wedge blocks II the plates are free to be removed readily from the skeleton drum for replacement when they are worn out. It will also be noted that since the plates rest upon the outer surfaces of the foot portions 8, none of the impact or abrasive action will act to loosen the clamping action of the wedge blocks on the plates.

The wedge blocks ll may be drawn inwardly of their openings .by any suitable means though I prefer to extend tie rods l4 between adjacent spanners, the tierods passing through longitudinal bores in the wedge blocks H and being provided with suitable nuts E5 on their ends so that by tightening the nuts iii the blocks H on adjacent spanners will be each drawn inwardly of their openings Ill and will securely clamp the plates in place. The tie rods l4 extending across the outer surface of the plates 4 intermediate the spanners may also be used as a ready means for reinforcing or strengthening or placing the plates 4 intermediate the spanners as by providing shoes 42 which extend between the tie rods l4 and the plates 4. Thus the tendency of the tie rods l4 to straighten out as they are tightened will act to brace the plates between their clamp edges.

It will also be noted that by employing this construction the wedge blocks H in adjacent openings along the lengthof the spanner may be disposed in opposite directions so that between each pair of tie rods i4 extending across one of the plates 4 there is a tiefrod Mextending across the adjacent plate on the opposite side of the spanner. V

' In Figs. 4 to 6 there is shown a'further improved form of spanner and block arrangement. In this instance the spanner 3a is of inverted T-shaped form in cross section including a base portion 8a and a web portion 9a the outer end of the web portion being formed with a head it preferably dove-tail shaped. The screen-like plate sections 4a rest on the base portions of the spanners 311 while an improved two-part block li, I8 is provided. The two-part block is also constructed in saddle-like form two parts being slidably connected longitudinally with respect to each other by suitable means such as a dovetailed tongue and groove connection It. The inner surfaces of the parts I! and H! are also provided with dove-tailed slots 20 of a slightly greater width at their outer edges than the edges of the head l6 so that when the blocks are slid toward each other and arranged in alignment they can be' fitted over the dove-tail shaped head l6 and then slid in opposite directions as shown in'Fig. 4 so that when the side wall of one part engages one side of the head i6 the opposite wall in the slot in the other block will engage the opposite surface of the head l6, so that the slanting or tapering surfaces 2| coact and produce a binding action on the cover plates 40.. 'Each part II, I3 is provided with a groove 22 for accommodating the rods Ma of the same type shown and described in connection with the form shown in Figs. 1, 2 and 3, that is, the tie rods exert a pull in opposite directions to effect a sliding and clamping engagement of the parts H and I8. Incidentally the tie rods completely encircle the screen or drum for reinforcing purposes.

It is believed in view of the foregoing that a further detailed description of the operation of the invention is unnecessary. Likewise it is believed that the advantages of the invention will be readily apparent.

Having thus fully described the invention what 15 claimed as new and desired to be secured by Letters Patent is:-

1. In a trommel screen construction, annular heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, said spanners having foot portions extending laterally of said drum to constitute shelves on which the side edges of adjacent screen I plates may rest exteriorly of said drum, said spanners having projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting on said foot portions, means for securing said. plates to said spanners including a wedge-shaped block extending through said projecting portion of said spanner immediately'above and engaging the outer surface of said plates, and means for drawing said block through said projecting portions of said spanner to wedge said block toward said plates and clamp the edges of said plates between said blocks and said foot portions.

2. In a trommel screen construction, annular heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, said spanners having foot portions. extending laterally of said drum to constitute shelves on which the side edges of adjacent screen plates may rest exteriorly of said drum, said spannershaving projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting on said foot portions,

means for securing said plates to said spanners including a plurality of openings extending through said projecting portions of said spanners and distributed along the length thereof, wedgeshaped blocks extending through said openings and immediately above the outer surfaces of-the edges of plates resting on the foot portions of said spanner, and means for drawing said blocks into said openings to cause said blocks to clamp the edges of said plates between said blocks and said foot portions of said spanners.

3. In a trommel screen construction, annular heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate'perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, said spanners having foot portions extending laterally of said drum to constitute shelves on which the side edges of adjacent screen plates may rest exteriorly of said drum, said spanners having projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting onsaid foot portions; means for securing said plates to said spanners including a plurality of openings extending through said projecting portions of said spanners and distributed along the length thereof, wedge-shaped blocks extending through said openings and immediately above the outer surfaces of the edges of both of the adjacent plates resting on the foot portions of said spanner, and means for drawing said wedge-shaped blocks. into said openings to cause said blocks to engage and clamp the adjacent edges of both plates between said blocks and the foot portions of said spanner.

4. In a trommel screen construction, annular heads, spanners. extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, said spanners having foot portions extending laterally of said drum to constitute shelves on which the side edges of adjacent screen plates may rest exteriorly of said drum, said spanners having projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting on said foot portions, means for securing said plates to said spanners including a plurality of openings extending through said projecting portions of said spanners and distributed along the length thereof, wedge-shaped blocks extending through said openings and immediately above the outer surfaces of the edges of both of the adjacent plates resting on the foot portions of said spanner and means extending between adjacent spanners for drawing the blocks on adjacent spanners inwardly of their openings to cause each of said blocks to engage and clamp the adjacent edges of the pair of plates resting upon the foot portions of each of said spanners between said blocks and said foot portions of said spanners.

5. In a trommel screen construction, annular heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, said spanners having foot portions extending laterally of said drum to constitute shelves on which the side edges of adjacent screen plates may rest exteriorly of said drum, said spanners having projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting on said foot portions, means for securing said plates to said spanners including a plurality of openings extending through said projecting portions of said spanners and distributed along the length thereof, wedge-shaped blocks extending through said openings and immediately above the outer surfaces of the edges of both of the adjacent plates resting on the foot portions of said spanner and means extending between adjacent spanners for drawing the blocks on adjacent spanners inwardly of their openings to cause each of said blocks to engage and clamp the adjacent edges of the pair of plates resting upon the foot portions of each of said spanners between said blocks and said foot portions of said spanners, and a shoe interposed between said last named means and the outer surface of said plates intermediate said adjacent spanners for reinforcing the plates intermediate their clamped edges.

6. In a trommel screen construction, annular heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantiallycylin drical screen, said spanners having foot portions extending laterally of said drum to constitute shelves on which the side edges of adjacent screen plates may rest exteriorly of said drum, said spanners having projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting on said foot portions, means for securing said plates to said spanners including a plurality of openings extending through said projecting portions of said spanners and distributed along the length thereof, wedgeshaped blocks extending through said openings v and immediately above the outer surfaces of the edges of said plates, means extending between adjacent spanners for drawing said blocks on adjacent spanners inwardly of their openings to cause said blocks to engage and clamp the edges of said plates between said blocks and the foot portions of said spanners upon which said plates rest.

7. In a trommel screen construction, annular heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, said spanners having foot por- H tions extending laterally of said drum to constitute shelves on which the side edges of adjacent screen plates may rest exteriorly of said drum, said spanners having projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting on saidfoot portions, means for securing said plates to said spanners including a plurality of openings extending through said projecting portions of said spanners and distributed along the length thereof, wedge-shaped blocks extending through said openings and immediately above the outer surfaces of the edges of said plates, means extending between adjacent spanners for drawing said blocks on adjacent spanners inwardly of their openings to cause said blocks to engage and clamp the edges of said plates between said blocks and the foot portions of said spanners upon which said plates rest, and a shoe interposed between said last named means and the outer surface of said plates intermediate said spanners to heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, said spanners being distributed in spaced relation about said heads, said spanners having foot portions extending laterally of said drum to constitute shelves on which the side edges of adjacent screen plates may rest exteriorly of said drum, said spanners having projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting on said foot portions, means for securing said plates to said spanners including a plurality of openings in said projecting portion of each of said spanners distributed along its length, wedge-shaped blocks extending through each of said openings immediately above and engaging the outer surface of the plates resting on said foot portions, and tie rods extending between adjacent spanners, engaging the blocks in said adjacent spanners to draw said blocks inwardly of said openings to clamp said plate edges between said blocks and said foot portions.

9. In a trommel screen construction, annular heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, said spanners being distributed in spaced relation about said heads, said spanners having foot portions extending laterally of said drum to constitute shelves on which the side edges of adjacent screen plates may rest exteriorly of said drum, said spanners having projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting on said foot portions, means for securing said plates to said spanners including a plurality of openings in said projecting portion of each of said spanners distributed along its length, wedge-shaped blocks extending through each of said openings immediately above and engaging the outer surface of the plates resting on said foot portions, and tie rods extending between adjacent spanners, engaging the blocks in said adjacent spanners to draw said blocks inwardly of said openings to clamp said plate edges between said blocks and said foot portions, and shoes disposed between said tie rods and the outer surface of said plates, intermediate said spanners whereby said tie rods act to reinforce said plates between the clamped edges thereof.

10. In a trommel screen construction, annular heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, said spanners having foot portions extending laterally of said drum to constitute shelves on which the side edges of adjacent screen plates may rest exteriorly of said drum, said spanners having projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting on said foot portions, means for securing said plates to said spanners including clamping blocks disposed above said foot portions of said spanners to rest upon the outer surface of said plates, said blocks comprising a wedge-shaped portion in contact with said projecting portion of said spanner and means extending circumferentially of said drum and engaging said blocks for drawing said blocks circumferentially of said drum and toward said foot portions to securely clamp the edges of said plates between said blocks and said foot portions of said spanners.

11. In a trommel screen construction, annular heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, each of said spanners having an inverted T-shaped cross section, the cross bar of said T constituting a foot portion and being disposed inwardly of said drum and the leg of said T extending radially outwardly of said drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, the opposite edges of said plates resting upon the outer surfaces of said foot portions of two adjacent spanners, a plurality of openings extending through the leg portion of said T, said openings being distributed throughout the length of said spanner, wedge blocks extending through said openings immediately above the surface of said plate resting upon said cross bar, and means for drawing said blocks into said openings to cause said blocks to engage and clamp the edges of said plates between said blocks and the foot portions of said spanners.

12. In a trommel screen construction, annular heads, spanners extending longitudinally between and interconnecting said heads to constitute a skeleton drum, a plurality of arcuate perforated screen plates disposed about the skeleton drum to form therewith a substantially cylindrical screen, said spanners having foot portions extending laterally of said drum to constitute shelves on which the side edges of adjacent screen plates may rest exteriorly of said drum, said spanners having projecting portions thereon projecting radially of said drum between the adjacent edges of plates resting on saidfoot portions, means for securing said plates to said spanners including a plurality of openings in the projecting portion of each of said spanners, an elongated block extending through each of said openings having one of its sides provided with a flattened portion to engage and rest upon the outer surface of the screen plates and having its opposite side tapering toward said first named side, and means for drawing said block into said opening to cause said flattened portion to engage and clamp said plate between it and the foot portion of said spanner.

JOHN A. TRAYLOR. 

